Litght source module arranged in an image scanning device for scanning a transparent object

ABSTRACT

A light source module arranged in an image scanning device having a scanning platform and an image-pickup module for scanning a transparent object is disclosed, The light source module includes a cover, a light source mounted in the cover for emitting light to the scanning platform for scanning a transparent object, a RGB filter mounted between the light source and the scanning platform for filtering off the light into RGB lights, a switching mechanism connected to the RGB filter for being controlled to alternately allow one of RGB lights to be transmitted to the scanning platform, and a transmission mechanism for carrying the light source, the RGB filter, and the switching mechanism to move with the image-pickup module for accomplishing the scanning operation to the transparent object.

FIELD OF THE INVENTION

[0001] The present invention relates to a light source module providedfor scanning a transparent object, and more particularly to a lightsource module arranged in an image scanning device for scanning atransparent object.

BACKGROUND OF THE INVENTION

[0002] As the scanner is continuously advancing in manufacturingtechniques and its price has dropped to a reasonable level, the scannernow has become an indispensable peripheral device for a standard PC.Owing to the rise of the processing speed of a central processing unit(CPU) in a standard PC and the requirement on high scanning quality fora standard PC user, the image scanning device capable of scanningvarious kinds of objects has already emerged in the scanner market. Forexample, an image scanning device which can respectively scan areflective object (such as a textbook) and a transparent object (such asa film).

[0003] Referring now to Fig.1, the flat-bed image scanning device of theprior art is implemented with using a contact image sensor (CIS) module11 as the image-pickup module. The CIS module 11 underneath the scanningplatform 10 is made up of a RGB light source 111, a rod lens 112, and asensor chip 113 so as to scan a colored reflective object on thescanning platform 10. While the user tends to scan a transparent objectwith a flat-bed image scanning device, a transparency adapter (TA) 12must be provided to be arranged in the flat-bed image scanning device inorder to provide a penetrative light. Unfortunately, the transparencyadapter (TA) 12 is able to provide a monochromatic light only, and thusit can not be applied to scan a colored transparent object.

[0004] Accordingly, the applicant tries to develop a light source modulearranged in an image scanning device for solving the problems sufferedfrom the prior art.

SUMMARY OF THE INVENTION

[0005] It is therefore an object of the present invention to provide alight source module arranged in an image scanning device for scanning atransparent object.

[0006] In accordance with a first preferred embodiment of the presentinvention, the image scanning device includes a scanning platform, animage-pickup module such as a contact image sensor (CIS) module, and alight source module. The light source module includes a cover, amonochromatic light source mounted in the cover for emitting amonochromatic light, a tricolor filtering device (i.e. RGB filters)mounted between the monochromatic light source and the scanning platformfor filtering off the monochromatic light into three differentmonochromatic (i.e. R, G, B) lights, a switching mechanism connected tothe tricolor filtering device for being controlled to alternately allowone of three different monochromatic lights to be transmitted to thescanning platform for scanning a transparent object, and a transmissionmechanism for carrying the monochromatic light source, the tricolorfiltering device, and the switching mechanism to move with theimage-pickup module for accomplishing the scanning operation to thetransparent object.

[0007] Preferably, the monochromatic light source is a cold cathodelamp. Moreover, the switching mechanism is implemented with a motor, andthe transmission mechanism includes a stepping motor and a guiding rod.

[0008] In accordance with a second preferred embodiment of the presentinvention, the image scanning device includes a scanning platform, animage-pickup module such as a contact image sensor (CIS) module, and alight source module. The light source module includes a cover, atricolor light source which is a RGB cold cathode lamp or a combinationof red LED array, a green LED array, and a blue LED array and mounted inthe cover for emitting three different monochromatic (i.e. R, G, B)lights to the scanning platform for scanning a transparent object, aswitching mechanism which may be implemented with a controlledmultiple-throw, single-pole switch and connected to the tricolor lightsource for being controlled to alternately allow one of three differentmonochromatic lights to be transmitted to the scanning platform, and atransmission mechanism for carrying the tricolor light source and theswitching mechanism to move with the image-pickup module foraccomplishing the scanning operation to the transparent object.

[0009] In accordance with a third preferred embodiment of the presentinvention, the image scanning device includes a scanning platform, animage-pickup module such as a contact image sensor (CIS) module, and alight source module. The light source module includes a cover, threemonochromatic light sources, each of which has the same color, e.g.three white cold cathode lamps, and mounted in the cover for emitting amonochromatic light, a tricolor filtering devices (i.e. RGB filters)connected to the three monochromatic light sources for filtering off themonochromatic light into three different monochromatic (i.e. R, G, B)lights, a switching mechanism which may be implemented with a controlledmultiple-throw, single-pole switch and connected to the three differentmonochromatic filtering devices for being controlled to alternatelyallow one of the three different monochromatic (i.e. R, G, B) lights tobe transmitted to the scanning platform for scanning a transparentobject, and a transmission mechanism for carrying the threemonochromatic light sources, the tricolor filtering devices, and theswitching mechanism to move with the image-pickup module foraccomplishing the scanning operation to the transparent object.

[0010] In accordance with a fourth preferred embodiment of the presentinvention, the image scanning device includes a scanning platform, animage-pickup module such as a contact image sensor (CIS) module, and alight source module. The light source module includes a cover, threemonochromatic light sources, each of which has a different color andmounted in the cover for emitting three different monochromatic lights(i.e. R, G, B) to the scanning platform for scanning a transparentobject, three guiding devices, each of which is connected to one end ofthe three monochromatic light sources for guiding the three differentmonochromatic lights (i.e. R, G, B) to the scanning platforn, aswitching mechanism which may be implemented with a controlledmultiple-throw, single-pole switch and connected to the three guidingdevices for being controlled to alternately allow one of the threedifferent monochromatic lights to be transmitted to the scanningplatform, and a transmission mechanism for carrying the three differentmonochromatic light sources, the three guiding devices, and theswitching mechanism to move with the image-pickup module foraccomplishing the scanning operation to the transparent object.

[0011] Now the foregoing and features of the present invention may bestbe understood through the following descriptions with reference to theaccompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic diagram showing the image scanning devicefor scanning a transparent object according to the prior art; and

[0013] FIGS. 2(a)-2(d) are schematic diagrams respectively showing fourembodiments of the image scanning device for scanning a transparentobject according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]FIG. 2(a) shows a first preferred embodiment of the image scanningdevice for scanning a transparent object according to the presentinvention. The image scanning device 2 includes a scanning platform 20and an image-pickup module 21. The light source module 22 includes acover 221, a light source being a cold cathode lamp 222, a RGB filter223, a switching mechanism 224 (which is implemented with a motor), anda transmission mechanism 225 including a stepping motor 2251 and aguiding rod 2252. The transmission mechanism 225 is used to carry thelight source 222, the RGB filter 223, and the switching mechanism 224together to move with the image-pickup module 21, while the switchingmechanism 224 is controlled to carry the RGB filter 223 to perform theswitch operation. Then, the light to be transmitted to the scanningplatform 20 will be alternated with red light, green light, and bluelight, thereby completing the scanning operation to a coloredtransparent object.

[0015]FIG. 2(b) shows a second preferred embodiment of the imagescanning device for scanning a transparent object according to thepresent invention. Equivalently, the image scanning device 2 alsoincludes a scanning platform 20 and an image-pickup module 21 similar tothose in FIG. 2(a). The light source module 22 includes also a cover221, a transmission mechanism 225 including a stepping motor 2251 and aguiding rod 2252. The major difference between FIG. 2(a) and FIG. 2 (b)is that the light source in FIG. 2(b) is a RGB cold cathode lamp or acombination of a red LED array 31, a green LED array 32, and a blue LEDarray 33 instead of a cold cathode lamp. The switching mechanism 224 canbe implemented with a controlled multiple-throw, single-pole switch.While the transmission mechanism 225 carries the light source (31, 32,33) and the switching mechanism 224 to move with the imagepickup module21, the switching mechanism 224 is controlled to perform switchoperation according to the ON and OFF state of the RGB cold cathode lampor RGB LED arrays (31, 32, 33), and then the light to be transmitted tothe scanning platform 20 will be alternated with red light, green light,and blue light.

[0016]

[0017]FIG. 2(c) shows a third preferred embodiment of the image scanningdevice for scanning a transparent object according to the presentinvention. It is to be noticed that unlike the light source module 220of FIG. 2(a), the light source module of FIG. 2(c) is implemented with acombination of three white cold cathode lamps (41, 42, 43) and a RGBfiltering device (44, 45, 46). The switching mechanism 224 can beimplemented with a controlled multiple-throw, single-pole switch. Withrespect to other components in the image scanning device, they aresimilar to the foregoing embodiments and thus we will not have a furtherdescription herein.

[0018]FIG. 2(d) shows a fourth preferred embodiment of the imagescanning device for scanning a transparent object according to thepresent invention. The light source module is implemented with acombination of three light guides (51, 52, 53) and a combination of ared LED array 54, a green LED array 55, and a blue LED array 56. Eachone of the RGB LED arrays (54, 55, 56) is respectively connected to oneend of the corresponding light guide (51, 52, 53). The switchingmechanism 224 can also be implemented with a controlled multiplethrow,single-pole switch. With respect to other components in the imagescanning device, they are similar to the foregoing embodiments and thuswe will not have a further description herein.

[0019] According to the above statements, the image scanning device forscanning transparent object of the present invention is capable ofemitting lights of three original colors (red, green, blue) to scan thetransparent object. Consequently, the color scanning operation can beachieved easily and the shortcomings encountered by the conventional TAcan be overcome thoroughly.

[0020] While the invention has been described in terms of what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention need not be limited to thedisclosed embodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures. Therefore, the above description and illustration should notbe taken as limiting the scope of the present invention which is definedby the following claims.

I claim:
 1. A light source module arranged in an image scanning devicehaving a scanning platform and an image-pickup module for scanning atransparent object, comprising: a cover; a monochromatic light sourcemounted in said cover for emitting a monochromatic light; a tricolorfiltering device mounted between said monochromatic light source andsaid scanning platform for filtering off said monochromatic light intothree different monochromatic lights; a switching mechanism connected tosaid tricolor filtering device for being controlled to alternately allowone of said three different monochromatic lights to be transmitted tosaid scanning platform for scanning said transparent object; and atransmission mechanism for carrying said monochromatic light source,said tricolor filtering device, and said switching mechanism to movewith said image-pickup module for accomplishing a scanning operation tosaid transparent object.
 2. A light source module as set forth in claim1 wherein said monochromatic light source includes a cold cathode lamp.3. A light source module as set forth in claim 1 wherein said tricolorfiltering device includes a RGB filter.
 4. A light source module as setforth in claim 1 wherein said switching mechanism is implemented with amotor.
 5. A light source module as set forth in claim 1 wherein saidtransmission mechanism includes a stepping motor and a guiding rod.
 6. Alight source module as set forth in claim 1 wherein said imagepickupmodule includes a contact image sensor (CIS) module.
 7. A light sourcemodule arranged in an image scanning device having a scanning platformand an image-pickup module for scanning a transparent object,comprising: a cover; a tricolor light source mounted in said cover foremitting three different monochromatic lights to said scanning platformfor scanning said transparent object; a switching mechanism connected tosaid tricolor light source for being controlled to alternately allow oneof said three different monochromatic lights to be transmitted to saidscanning platform; and a transmission mechanism for carrying saidtricolor light source and said switching mechanism to move with saidimage-pickup module for accomplishing a scanning operation to saidtransparent object.
 8. A light source module as set forth in claim 7wherein said tricolor light source includes a RGB cold cathode lamp. 9.A light source module as set forth in claim 7 wherein said tricolorlight source includes a combination of a red LED array, a green LEDarray, and a blue LED array.
 10. A light source module as set forth inclaim 7 wherein said switching mechanism is implemented with acontrolled multiple-throw, single-pole switch.
 11. A light source moduleas set forth in claim 7 wherein said transmission mechanism includes astepping motor and a guiding rod.
 12. A light source module as set forthin claim 7 wherein said image-pickup module includes a contact imagesensor (CIS) module.
 13. A light source module arranged in an imagescanning device having a scanning platform and an image-pickup modulefor scanning a transparent object, comprising: a cover; threemonochromatic light sources, each of which has the same color andmounted in said cover for emitting a monochromatic light; a tricolorfiltering device connected to said three monochromatic light sources forfiltering off said monochromatic light into three differentmonochromatic lights; a switching mechanism connected to said tricolorfiltering device for being controlled to alternately allow one of saidthree different monochromatic lights to be transmitted to said scanningplatform for scanning said transparent object; and a transmissionmechanism for carrying said three monochromatic light sources, saidtricolor filtering device, and said switching mechanism to move withsaid image-pickup module for accomplishing the scanning operation tosaid transparent object.
 14. A light source module as set forth in claim13 wherein said three monochromatic light sources include three whitecold cathode lamps.
 15. A light source module as set forth in claim 13wherein said three different monochromatic filtering devices includes acombination of a red filter, a green filter, and a blue filter.
 16. Alight source module as set forth in claim 13 wherein said switchingmechanism is implemented with a controlled multiple-throw, single-poleswitch.
 17. A light source module as set forth in claim 13 wherein saidimage-pickup module includes a contact image sensor (CIS) module.
 18. Alight source module arranged in an image scanning device having ascanning platform and an image-pickup module for scanning a transparentobject, comprising: a cover; three monochromatic light sources, each ofwhich has a different color and mounted in said cover for emitting threedifferent monochromatic lights to said scanning platform for scanningsaid transparent object; three guiding devices, each of which isconnected to one end of said three monochromatic light sources forguiding said three different monochromatic lights to said scanningplatform; a switching mechanism connected to said three guiding devicesfor being controlled to alternately allow one of said three differentmonochromatic lights to be transmitted to said scanning platform; and atransmission mechanism for carrying said three different monochromaticlight sources, said three guiding devices, and said switching mechanismto move with said image-pickup module for accomplishing a scanningoperation to said transparent object.
 19. A light source module as setforth in claim 18 wherein said three monochromatic light sources includea combination of red LED array, a green LED array, and a blue LED array.20. A light source module as set forth in claim 18 wherein said threeguiding devices includes three light guides.
 21. A light source moduleas set forth in claim 18 wherein said switching mechanical isimplemented with a controlled multiple-throw, single-pole switch.
 22. Alight source module as set forth in claim 18 wherein said imagepickupmodule includes a contact image sensor (CIS) module.